Artificial tooth.



N0.'797,312. PATENTED AUG. 15, 1905. H. P. OSBORN.

ARTIFICIAL TOOTH. v

APPLICATION FILED MAY 9, 1904.

Fllf l llillll Wlftrt'lUFlQ HENRY P. OSBORN, OF BAYONNE, NEl V JFREBEY.

lilo. 797,31 2.

Specification of Letters Patent.

Patented Aug. 15, 1905.

Application filed May 9,1904. Serial No. 207,104.

To rnZZ 70/2/0710 it 'H'MLZ/ concern/x Be it known that l,HENRYP.0SBORN, a citizen of the United Etates, residing at Bayonne, inthe county of Hudson and State of New Jersey, have invented a new anduseful Artificial Tooth, of which the following is a specification.

ll/ly invention relates to improvements in artificial teeth, andcomprises an improved method of inserting and attaching artiiicialteeth.

My invention further consists in a rootband flattened in front to seatin a step formed in the front side of a root, in the combination withsuch band of a tooth-facing covering the front of said band and likewiseadapted to be seated in said step, and in the combination with such bandof a canal-post secured thereto; and my invention further comprises anovel tooth-face.

Uther features comprised in my invention will be described hereinafterand particularly pointed out in the claims.

The objects of my invention are to permit the renewal at will of brokenor injured teeth or tooth facings whether the same be in crown-teeth, inplates, or in bridges; to conceal from view the joints between crownsand the roots to which they are applied; to avoid projection ofartificial teeth beyond the normal line; to provide an artificial toothwhich shall closely simulate in appearance the natural tooth, whichshall not expose its metal parts to view, and which shall have greatstrength and durability, and generally to improve and strengthen theconstruction of artil'icial teeth and to permit the ready repairthereof.

ll will now proceed to describe my invention with reference to theaccompanying drawings, in which certain constructions of artificialteeth or dentures embodying my invention are illustrated, and will thenpoint out the novel features in claims.

Figure 1 shows a vertical section of a toothcrown and of a root to whichthe same is attached, the root having formed thereon on its front side astep in which both the rootband and the upper portion of the facing areseated. Figs. 2 and 3 show, respectively, side and front views of a rootstepped according to my invention to receive a crown. Fig.

at shows a vertical section of a crown prepared for attachment to aroot, the construction of the tooth-face and of the band being slightlydifferent from the construction shown in Fig.

1. Fig. 5 shows a vertical section through a bicuspid crown and root.Fig. 6 shows an other vertical section through a bicuspid crown androot, illustrating an alternative construction. Fig. '7 shows a verticalsection taken on a plane parallel to the front of the tooth of a crownin place on a root. Fig. 8 shows a vertical section on a plane at rightangles to Fig. 7 of the same crown and root and illustrates theattachment of the toothface to the band by pins instead of by screws.

Fig. 9 shows a cross-section of a band and. root on a planesubstantially perpendicular to the axis of the root, the section beingtaken on the line 1 lot Fig. 7. Fig. 10 shows a partial section andpartial top view of a bridge comprising root-bands flattened to fit uponroots which have been stopped in ac cordance with my invention. Fig. 11shows a vertical section through the bridge on the line 2 2 of Fig. 10.Fig. 12 shows a detail cross-section through a root which has beenhanded according to my invention, the view illustrating the use of aconnecting-piece between the band and canal-post when said post is notimmediately adjacent to the front flattened portion of the band. Fig. 13is a vertical sectional view of a crown-tooth of the Richmond type andillustrates the use in such. teeth of screw-threaded tooth-faces and theattachment of such faces to the bands and the backings thereof by meansof screws. Fig. let shows a central vertical section of a gumtooth blockprovided with a removable screwthreaded tooth-face held in place by ascrew. Fig. 15 shows a vertical section of a dental plate provided witha removable tooth-face which is screw-threaded and is held to thebacking of said plate by means of screws.

1 will first describe my invention in its application to crown-teeth andwill then describe its application to bridges and plates.

Referring first to Figs. 1 to 9, inclusive, illustrating the applicationof my invention to crown-teeth, in said figures reference-letter Adesignates a tooth-face formed of porcelain or other suitable material;B, a fasteningpin by which said face is attached to the band; i), thesaid band; E, a canal-post secured to said band; F, the natural root,and Gr a metal backing forming a part of the band and to which the faceA is secured.

in applying a crown-tooth to a natural root according to my preferredmethod after the root has been cut oil to the proper length, as iscustomary in crownwork, a step is formed in its front side by grindingaway the front of the root. Such step, as shown in Fig. 8, preferablyextends above the edge of the gum, so that when the gum grows down totake the place of such portion of it as may be cut away during theforming of the step it will cover the joint between the root and crown.Said step also preferably extends inward to a point such that thecanal-post when inserted in the tooth will be flush with the back ofsaid step. Over the elevated portion of the root remaining after theforming of the step the rootband Dis next placed. This root-bandencircles the said elevated fraction of the root and is flattened infront to seat in the step formed in the root, as above described. Saidband has attached to it the canal-post E, which serves to anchor thecrown firmly to the root. The root band by encircling the elevatedfraction of the root preserves the latter from decay and prevents itfrom splitting. The band D is provided with a projecting portion G,forming a backing for the tooth-face A. Said tooth-face is customarilyformed of porcelain, is curved on its front side to correspond to thecurvature and proportions of the natural tooth, and at its upper or gumend is seated in the said step formed in the natural root, for whichpurpose the tooth-face is frequently notched or recessed at its upper orgum end, as indicated in Figs. 1, 5, 6, and 8. Said tooth-face may beattached to the backing, as indicated in Fig. 8, by pins B, baked intothe porcelain face and having their ends brazed or soldered into thebacking; but preferably I employ screw-threaded pins B, as shown inFigs. 1, 4, 5, and 6, screwing into threads formed in the porcelainitself. This method of attaching the face has the great advantage thatif the face is broken, cracked, or chipped in any way it may be removedand a new face applied in its place with little trouble and at littleexpense. This advantage, of much importance in crown and bridge teeth,is of equal importance in plate-teeth, to which reference will be madehereinafter.

To secure the face properly to the backing by means of a screw, it isimportant that the screw-threads formed in the porcelain shall be offine pitch and perfectly formed. This is a matter of great difficulty,if not absolutely impossible, by former methods of forming such threadsin porcelain; but 1 have found that the threads may be formed veryperfectly and of as line pitch as desired by employing a metal bushingthreaded on the outside to correspond to the threads to be formed in theporcelain. This bushing, which preferably is of platinum, is placedwithin the toothmold used in forming the porcelain tooth, and the toothsubstance is pressed in and around it. This bushing or matrix remains inthe tooth during the subsequent baking of the latter and after thebaking is removed from the porcelain by means of a suitable solventwhich dissolves the matrix, leaving in the porcelain veryperfectly-formed screwthreads. There is no loss of platinum, as thelatter may be recovered from the solvent used, and hence the use of thisexpensive metal in the matrix is not precluded on the ground of expense.It is obvious that by employing matrices of different shapes other formsof recesses may be formed in the porcelain.

The method above described of forming screw-threads, grooves, overhangs,and the like in porcelain and similar vitreous materials or materialswhich are molded or pressed to shape forms the subject-matter of adivisional application for Letters Patent.

Obviously the tooth-facing having formed in it a screw-threaded recessadapted to receive a fastening-screw may be employed in other types ofcrowns besides those illustrated in Figs. 1 to 8 inclusive. Fig. 13shows such a face employed in a crown of the Richmond type.

Porcelain tooth-faces provided with screwthreads adapted to receive afastening-screw may also be employed with great advantage in dentalplates. Such a tooth-face may be removed from the plate if broken orotherwise injured and replaced by a new tooth or face of similar form,thus avoiding an expensive and ditficult repair, such as is required incase a tooth of a dental plate as heretofore constructed is broken orinjured, and the removal of the broken tooth or tooth-face attachedaccording to my invention can be done very quickly, as can the insertionof a new tooth or face, and no special skill is required. Fig. 14: showsa gum tooth-block provided with a removable tooth A separate from thegum portion J of the block and held in place by a screw B. Obviously inthe case of a plate comprising a gum block or blocks constructed asshown in Fig. 16 in case one of the tooth-faces breaks it is the work ofbut a moment to unscrew the corresponding fastening-pin and remove thebroken tooth-face and replace it by a similar perfect tooth.

Fig. 15 shows a metal dental plate K of the type which are struck up indies. The teeth of this plate comprise faces A, removably secured tobackings B, attached to said plate, the particular means employed forattaching the faces to the backings being screws. The upper edges of thefaces project up under and are covered by the artificial or imitationgum of the plate. so that the plate thus formed very closely imitates inappearance the natural teeth.

The method of attaching crowns to teeth above described and the methodof attaching vitreous tooth faces to the bands of such crowns areobviously applicable to bridges as well as to single teeth. Figs. 10 and11. show a bridge so constructed. H is the bridge proper, anchored atthe ends, as is customary, to natural roots. The crown-bands D, by whichthe "roasts an bridge is secured to thenatural roots, are simi lar tothe crown bands employed in single teeth and have faces similarlyapplied. The portion of the bridge intermediate the natural roots maylikewise have removable toothfaces.

As shown in Fig. l], the bridgeinay be removed for cleaning byunscrewing nuts 1.

"lVhcn it is not convenient or desirable to attach the canal-post Edirectly to the front flattened portion of the band I), I connect saidpost to the band by means of a connectingpiece if, as shown in Fig. 12.

ilrfy improved screw-threaded tooth-face may also be employed incrowirteeth of other types besides those shown in Figs. 1 to 9,inelusive.

lf ig. 13 shows a tooth of what is known as the Richmond type, havingits face screwthreaded and held in place by a screw. The face so heldmay be removed readily if injured and replaced by another face, whichcannot be done when the faces are secured in place accoriiling to themethods n ow commonly used.

ft is obvious that my invention is susceptible of many and variedmodifications without departing from the spirit and scope thereof, thatin the construction of the various parts many different materials may beused, and that certain parts may be used in connection with other partsof different construction. ffhereforc i do not limit myself to theparticular details of construction herein illustrated and described orto any particular material from which to form the teeth or tooth faces,the bands, the bridges, or the plates.

W hat l claim is l. in an artificial tooth, the combination of aroot-band flattened in front to seat in a step formed on the front sideof a root, a tooth-fac ing, and means for securing the same to saidband.

2. in an artificial tooth, the combination of a root-band flattened infront to seat in a step formed on the front side of a root, atooth-facing, and means detachably securing said facing to said band.

3. lfn an artificial tooth, the combination of a root'band flattened infront to seat in a step formed on the front side of a root, a tooth-facing covering the front of said band and like wise adapted to be seatedin said step, and means for securing the facing to said band.

4.. lfn an artificial tooth, the combination of a root-band fiattencd infront to seat in a step formed on the front side of a root, atoothfacing covering the front of said band and recessed to be seated insaid step, and means detachably securing said facing to said band.

in an artificial tooth, the combination of a root-band flattened infront to seat in a step formed on the front side of a root, a canalpostsecured to said band, a tooth-facing, and means for securing the same tosaid band.

f3. lfn an artificial tooth, the combination of a root-band flattened infront to seat in a step formed on the front side of a root, a canalpostsecured to said band, a tooth'facing, and means detachably securing saidfacing to said band.

7. in an artificial tooth, the combination of a root-band flattened infront to seat in a step formed on the front side of a root, a canalpostsecured to said band, a tooth-facing covering the front of said band andrecessed to be seated in said step, and means for securing the facing tosaid band.

8. lfn an artificial tooth, the col'nbination of a root-band flattenedin front to seat in a step formed on the front side of a root, acanalpost secured to said band, a tooth-facing covering the front ofsaid band and recessed to be seated in said step, and means detachablysecuring the facing to said band.

fl. A root-band adapted to surround the portion of a root remainingafter the formation of a step in the front of said root, said bandflattened in front to seat in said step.

if). A root-band adapted to surround the portion of a root remainingafter the formation of a step in the front of said root, said bandflattened in front to seat in said step, in combination with acanal-post secured to said band.

if. A rootband adapted to surround the portion of a root remaining afterthe formation of a step in the front of said root, said band flattenedin front to seat in said step, in combination with a canal-post securedto the front flattened portion of said band.

12. in an artificial tooth, the combination of a scrmv-threaded vitreousfacing, a root-band provided with a projecting backing against whichsaid facing lies, and a screw passing through said backing, engaging thethreads of said facing, and serving to hold said facing to the backing.

13. In an artificial teeth, the combination of a screw-threaded vitreousfacing, a root-protecting band having its front side flattened, and ascrew engaging the threads of said facing and holding the latter to saidband.

lef. in an artificial tooth, the combination of a screw-tln'eadedvitreous facing, a root-protecting band having its front side flattened,a caiial- 'iost secured to said band, and a screw engaging the threadsof said facing and holding the latter to said band.

15. .In an artificial-tooth structure, the combination with a root-bandhaving a front fiattencd portion the face of which is back of the normalposition for the front of the tooth, said band having a projectingtooth-backing, of a removable face covering the front of said backingand the front flattened portion of said band, and secured to saidbacking.

16. As an article of manufacture, a detachable tooth-face formed ofporcelain or other suitable material, having its front side curved tocorrespond with the curvature of the face of the natural tooth, and itsrear side having I on its rear side, a flat-surfaced notch for peraflat-surfaced notch at its root end to seat in initting seating of theface in a stepped root, a notch-like step in the face of a root, saidthe cutting edge of said face being tapered; face beveled ofi at itscutting end, so as to said face being provided, near its thickest leavesaid face thickened at one point, and part, with supporting means.

tooth -face having a screw: threaded hole HENRY P. OSBORN' ormed in suchthickened pal t.

17. As an article of manufacture, a tooth- I itnesses:

face conveXly curved on its front side to nat- H. A. LOOMIS, uralproportions, and having at its gurn end, R. A. GARDEN.

